Injector having swirl structure downstream of valve seat

Abstract

An atomizing injector comprises a body having a central bore with a valve situated in the bore, leading to a chamber. An actuator moves the valve between closed condition and open conditions, selectively exposing the chamber to a flow of pressurized liquid. A discharge port extends from the chamber to a discharge orifice. A swirl element is situated in the chamber, while leaving a free space in the chamber immediately above the discharge port. When the valve is opened, liquid flows into the chamber, through the swirl element into the space, forming a whirl in the space before passing through the discharge port and exiting the discharge orifice as an atomized whirling spray.

The invention claimed is: 
     
       1. An injector comprising:
 a longitudinal body; 
 a central bore in the body, having upper and lower ends and a source volume for receiving pressurized fluid to be injected; 
 a valve situated in the bore, having a moveable sealing face selectively seated against a stationary sealing face; 
 a chamber in selective fluid communication with the source volume through said valve; 
 a control system that selectively moves the valve member into a closed condition whereby said moveable face seals against said stationary face and into an open condition whereby the moveable face lifts from said stationary face; 
 a discharge port from the chamber to a discharge orifice; 
 a swirl element situated in the chamber, while leaving a free space in the chamber immediately above the discharge port; 
 whereby when the valve is in said closed condition, no fluid can enter said chamber from the source volume and when the valve is in said open condition, pressurized fluid flows into said chamber, through said swirl element into said space, forming a whirl in said space before passing through said discharge port and exiting said discharge orifice as an atomized whirling spray; further comprising 
 a generally cup shaped insert ( 518 A,  618 A) having a side wall and a bottom wall, located at and fixed with respect to the bottom of the bore, defining a cylindrical ( 514 ,  614 ) chamber below the valve seat and a single discharge orifice ( 516 ,  616 ) from the chamber at the bottom wall, coaxial with the bore; 
 a generally cylindrical plug ( 528 ,  628 ) coaxially situated within the insert, having a side wall spaced radially from the sidewall of the insert and defining a flow passage ( 514 ,  614 ) between the insert and the plug, and a bottom adjacent the bottom of the insert; 
 at least two radially oriented slots ( 522 ,  622 ) between the bottom of the plug and the bottom of the insert, each slot having an outer portion in fluid communication with said flow passage ( 514 ,  614 ) between the insert and the plug and narrowing toward the axis of the plug; and 
 a cylindrical space ( 520 ,  620 ) between the bottom of the plug and the bottom of the insert in direct fluid communication with the discharge orifice ( 516 ,  616 ), 
 wherein the slots and cylindrical space are formed in the bottom of the plug. 
 
     
     
       2. An injector comprising:
 a longitudinal body; 
 a central bore in the body, having upper and lower ends and a source volume for receiving pressurized fluid to be injected; 
 a valve situated in the bore, having a moveable sealing face selectively seated against a stationary sealing face; 
 a chamber in selective fluid communication with the source volume through said valve; 
 a control system that selectively moves the valve member into a closed condition whereby said moveable face seals against said stationary face and into an open condition whereby the moveable face lifts from said stationary face; 
 a discharge port from the chamber to a discharge orifice; and 
 a swirl element situated in the chamber, while leaving a free space in the chamber immediately above the discharge port; 
 whereby when the valve is in said closed condition, no fluid can enter said chamber from the source volume and when the valve is in said open condition, pressurized fluid flows into said chamber, through said swirl element into said space, forming a whirl in said space before passing through said discharge port and exiting said discharge orifice as an atomized whirling spray; further comprising 
 a generally cup shaped insert ( 518 A,  618 A) having a side wall and a bottom wall, located at and fixed with respect to the bottom of the bore, defining a cylindrical ( 514 ,  614 ) chamber below the valve seat and a single discharge orifice ( 516 ,  616 ) from the chamber at the bottom wall, coaxial with the bore; and 
 a generally cylindrical plug ( 528 ,  628 ) coaxially situated within the insert, having a side wall spaced radially from the sidewall of the insert and defining a flow passage ( 514 ,  614 ) between the insert and the plug, and a bottom adjacent the bottom of the insert; 
 wherein the plug has a lower portion spaced from the sidewall of the insert for defining said flow passage, an upper portion extending above the insert, and a flange extending radially over the sidewall of the insert; 
 a spring bearing on the flange to urge the plug toward the bottom of the insert; and 
 flow openings in the flange leading to said flow passage between the plug and the insert.